Blogging has grown rapidly on the internet over the last few years. Weblogs, referred to as blogs, span a wide range, from personal journals read by a few people, to niche sites for small communities, to widely popular blogs frequented by millions of visitors, for example. Collectively, these blogs form a distinct subset of the internet known as blogspace, which is increasingly valuable as a source of information for everyday users.
Search engines are increasingly implementing features that restrict the results for queries to be from blog pages. The website www.blogcensus.net gives information on an effort to index blogs, though this was apparently discontinued in late 2003. At that time, the site stated that it had indexed 2.8 million blogs. Currently, Technorati claims to be tracking 43.2 million blog sites. It is currently difficult for search engines to identify blog pages, regardless of the source of the content in a blog page.